Journal of Yeungnam Medical Science

Suck Kang Lee

19 Articles

The Effect of Long Chain N-3 Polyunsaturated Fatty Acids on Development of Collagen-induced Arthritis in Rats.: Kyung Ho Shin, Se Dong Kim, Hwan Jin Jeon, Eung Chan Jang, Suck Kang Lee; Yeungnam Univ J Med. 2002;19(1):39-48. Published online June 30, 2002; DOI: https://doi.org/10.12701/yujm.2002.19.1.39

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Abstract PDF: BACKGROUND
The treatment of rheumatoid arthritis still depend on conserve therapy in major. Recent studies report that n-3 polyunsaturated fatty acids(PUFA) could modulate the incidence and progress of arthritis. The purpose of this study was to investigate the effects of n-3 PUFA on the development of collagen-induced arthritis in rats. MATERIALS AND METHODS: Female Louvain rats were used for this experiment. Rats were randomly assigned into either normal(n=8) or collagen-immunized groups, and collagen immunized groups were divided into control(n=8, normal diet) and n-3 PUFA(n=8, 5% n-3 PUFA in diet) groups. One week after feeding n-3 PUFA to rats, they were immunized with type II collagen emulsified in incomplete Freund's adjuvant into tail and back. Development of arthritis was confirmed by x-ray and microscopic examination. RESULTS: Incidence of arthritis at the 5th week after immunization was 38% in control and 0% in n-3 PUFA. Rats with arthritis showed edema in hind paws and inflammation in synovial membrane of the knee joint. Plasma glucose and insulin were not changed by both of immunization and diet. Plasma triglycerides and cholesterol concentrations were decreased by n-3 PUFA. CONCLUSION: n-3 PUFA may prevent or treat collagen-induced arthritis in rats. Further studies are needed for action mechanism of it.

Effect of Age on Glucose Metabolism of Skeletal Muscle in Rats.: Eung Chan Jang, Woon Ki Youn, Suck Kang Lee; Yeungnam Univ J Med. 2001;18(1):94-100. Published online June 30, 2001; DOI: https://doi.org/10.12701/yujm.2001.18.1.94

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BACKGROUND
It is doubtful that aging causes deteriorated glucose metabolism and insulin resistance of skeletal muscle. Some researchers had different results about it. So we have studied the mechanism responsible for the abnormal glucose tolerance associated with aging in rapidly growing and matured rats. MATERIALS AND METHODS: Animals were used S.D. rats. Growing rats were 7 weeks old (BW: 160-190 gm) and matured rats were 28 weeks old (BW: 420-525 gm). RESULTS: Fasting blood glucose and plasma insulin levels were significantly elevated in matured rat compared with growing rats. And during oral glucose tolerance test the glucose level was also significantly elevated in matured rats. These results confirmed an insulin resistant state of aging. Insulin levels at 30 minutes of oral glucose tolerance test was significantly elevated in growing rat. But at 120 minutes it was maintained at higher level in matured rats than in growing rats. It suggested the possibility of increased insulin secretion by initial stimulation of beta-cells in growing rats, and increased secretion and decreased catabolic rate of insulin in matured rats. Glucose uptake rate of soleus muscle in matured rats was lower than that of growing rats, but the difference was not statistically significant. The dose(insulin)- responsive (glucose uptake) curve of soleus muscle was only slightly deviated to the right side. CONCLUSION: Glucose metabolism of rat skeletal muscle was worsened by aging. The data of glucose uptake experiments suggested the possibility of insulin resistance of skeletal muscle in matured rats, but the mechanism of insulin resistance of skeletal muscle need further studies.

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Anti-Oxidative Effect of Jeokbaekhaogwanjoong-tang Distillate on Spleen Cells of Aged Rats
Young-Chun Park, Il-Gu Kim, Tae-Min Kim
The Korea Journal of Herbology.2016; 31(4): 35. CrossRef
The Effect of Jeokbaekhaogwanjung-tang Herbal Acupuncture Solution on the Immune Activity of Spleen Cells of Aged Rats
Hyun-Suk Lee, Kang-Min Choi, Yun-Kyoung Yim
Journal of Korean Medicine.2016; 37(1): 90. CrossRef
The Effect of Yongyukjowitang Distillate on the Immune Activity of Spleen Cells of Aged Rats
Jin-Wook Yi, Moon-Hee Jang, Jae-Song Choi, Taek-Won Ahn
Journal of Sasang Constitutional Medicine.2013; 25(3): 218. CrossRef

Effect of Exercise on Antioxidant Enzyme Activities of Skeletal Muscle and Liver in STZ-diabetic Rats.: Kwang Ho Seok, Suck Kang Lee; Yeungnam Univ J Med. 2000;17(1):21-30. Published online June 30, 2000; DOI: https://doi.org/10.12701/yujm.2000.17.1.21

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Abstract PDF: BACKGROUND
The purpose of the present study was to investigate the effect of exercise on the activities of antioxidant enzymes, superoxide dismutase(SOD), glutathione peroxidase(GPX) and catalase(CAT) of skeletal muscle(gastrocnemius) and liver in streptozotocin(STZ) induced diabetic rats. The malondialdehyde(MDA) concentration was also measured as an index of lipid peroxidation of the tissues by exercise-induced oxidative stresses in the diabetic rats. MATERIAL AND METHODS: Male Sprague-Dawley rats were randomly divided into control and STZ-induced diabetic rats. The STZ in citrate buffer solution was injected twice at 5 days intervals intraperitoneally(50, 70 mg/kg respectively). On the 28th day after the first STZ injection, the diabetic animals were randomly divided into pre- and post-exercise groups. The exercise was introduced to the rats of post-exercise group by treadmill running till exhaution with moderate intensity (VO2max: 50-70%) of exercise. The duration of average running time was 2 hours and 19 minutes. RESULTS: The blood glucose concentration was increased(p<0.001) and plasma insulin concentration was decreased(p<0.001) in the diabetic rats. The glycogen concentration in the muscle and liver was decreased by exhaustive exercise in the diabetic rats(p<0.001). In the skeletal muscle, the activities of GPX was increased(p<0.05) and the activities of SOD and CAT were not changed in the diabetic rats compare to the control rats. The activities of GPX was not changed by exercise but the activities of SOD(p<0.01) and CAT (p<0.01) were decreased by exercise in the diabetic rats. The concentration of MDA was not changed by exercise in diabetic rats. and the values of pre-exercise and post-exercise diabetic rats were not different from the value of control rats. In the liver, the activities of SOD was decreased(p<0.01) and the activities of GPX and CAT were not changed in diabetic rats compared to the values of control rats. The activities of SOD, GPX and CAT were not changed by exercise in diabetic rats but the the slight decreasing tendency of the activity of SOD was observed. The MDA concentration was increased in the diabetic rats compared to the values of control rats(p<0.001) but there was no change of MDA concentration by exercise in diabetic rats. CONCLUSIONS: In summary, the exhaustive physical exercise has not been shown to impose oxidative stress on skeletal muscle due to oxygen free radicals regardless of decreament of SOD and CAT in the diabetic rats. In liver tissue, the tissue damage by oxidative stress was observed in diabetic rats but the additional tissue damage by the exhaustive physical exercise was not observed.

Effects of Regular Treadmill Running on GLUT4 Protein of Skeletal Muscle in STZ-diabetic Rats.: Jong yeon Kim, Hyung il Bae, So young Park, Yong woon Kim, Suck kang Lee; Yeungnam Univ J Med. 1998;15(2):341-349. Published online December 31, 1998; DOI: https://doi.org/10.12701/yujm.1998.15.2.341

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Abstract PDF: The purpose of this study was to investigate the effects of regular treadmill running on GLUT4 protein of skeletal muscle in STZ-diabetic rats. I used 19 male Sprague-Dawley rats weighing 140 to 160 grams. Rats were randomly assigned into normal, diabetes(DM) and DE(DE) groups. The exercise was loaded with treadmill running for 5 days per week during 4 weeks. All experimental procedures were carried out following overnight fasting 48 hours after last exercise. Gain(gm) in body weight in DM rats(82+/-2.4) was lowered compared to normal rats(109+/-2.8), and decreased by exercise. Plasma glucose concentration(mg/dl) in DM rats was 143+/-3.1 which is higher than that of normal group of 103+/-6.4. The concentration of DE group was lower than that of DM rats. Plasma insulin concentration(micronU/ml) of DM and DE rats was significantly lowerd compared to normal rats. There was no difference of plasma concentrations of FFA and HDL cholesterol among noraml, DM and DE groups. Plasma triglyceride concentration(mg/dl) was significantly highered in DM group compared to those of DM group, the concentration of DE group was lower. Glycogen concentration(mg/gm wet weight) of the plantaris muscle in DM and DE groups was significantly reduced compared to normal group. Glucose transporter 4(GLUT4) protein of soleus was analyzed by Western blot. In DM group, the GLUT4 protein level was markdly decreased compared to normal group, but the level was recovered to the level of normal group by 4 weeks treadmill running. In conclusion, the insulin resistance induced by STZ administration was partially improved by 4 weeks physical training in rats.

Effect of Hyperglycemia and Hyperlipidemia on Cardiac Muscle Glycogen Usage during Exercise in Rats.: Suck Kang Lee, Eun Jung Kim, Yong Woon Kim; Yeungnam Univ J Med. 1998;15(1):29-35. Published online June 30, 1998; DOI: https://doi.org/10.12701/yujm.1998.15.1.29

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Abstract PDF

Rats were studied during 45 minutes treadmill exercise to determine the effects of hyperglycemia and hyperlipidemia on the utilization of cardiac muscle glycogen, and the utilization of diaphragm muscle glycogen was also studied for comparing to cardiac muscle. The hyperglycemia was produced by ingestion of 25% glucose solution(1ml/100gm, BW) and the hyperlipidemia by 10% intralipose ingestion(1ml/100gm, BW) with intraperitoneal injection of heparin(500 IU) 15 minutes before treadmill exercise. The mean blood glucose concentrations(mg/dL) in control and hyperglycemic rats were 110 and 145, respectively, and the mean plasma free fatty acid concentrations(micronEq/L) in control, control exercise(control-E) and hyperlipidemia exercise(HL-E) rats were 247, 260 and 444, respectively. In the hyperglycemic trial, the cardiac muscle glycogen concentration was not significantly decreased by the exercise but the concentration in control rats was decreased to 73.9%(p<0.05). The glycogen concentration of diaphragm was significantly decreased in both groups by the exercise, but the hyperglycemia decreased the glycogen utilization by approximately 10% compared to the control. The cardiac muscle glycogen concentration was not decreased by the exercise in control and hyperlipidemic rats but the utilization of glycogen in hyperlipidemic rats is lower than that of the control. These data illustrate the sparing effect of hyperglycemia on cardiac muscle glycogen usage during exercise, but the effect of hyperlipidemia was not conclusive. In the skeletal muscle, the usage of glycogen by exercise was spared by both hyperglycemia and hyperlipidemia.

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The Effects of Treadmill Exercise on Blood components, Antioxidant enzymes and Reactive Oxygen in Hyperlipidemic Rats
Byeong-Ok Jung, Sang-Hun Jang, Hyun-Soo Bang
Journal of the Korean Society of Physical Medicine.2013; 8(1): 71. CrossRef

Utilization of Supercompensated Glycogen of Hindlimb Muscles during Strenous Exercise in Rats.: Chun Bae Jun, Jong Chul Ahn, Dae Deup Song, Suck Kang Lee; Yeungnam Univ J Med. 1997;14(1):137-154. Published online June 30, 1997; DOI: https://doi.org/10.12701/yujm.1997.14.1.137

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Abstract PDF: The aim of the present investigation has been to evaluate the depletion pattern of the supercompensated glycogen of hindlimb muscles during strenous exercise in rats. The plan of the maximizing muscle glycogen stores is based on the fact that a glycogen-depleted muscle by exercise will have an increased avidity for glycogen when exposed to a high carbohydrate diet. The glycogen concentration of soleus, red gastrocnemius and plantaris muscle, and liver was measured at 0, 30 and 60 minutes during treadmill exercise. The experimental animals were divided into 5 group - Normal(N), Control(C), 1Hour(1HR:after 1hour of glucose ingestion), 2Hour(2HR:after 2hour of glucose ingestion) and Exercise-1Hour(EX-1HR:glucose ingestion after 1 hour of preloading treadmill exercise)group - for glycogen storage study. The glycogen concentration of soleus, red gastrocnemius and plantaris muscles in N group was 4.57+/-0.34, 5.11+/-0.24 and 6.55+/-0.20 mg/gm wet wt., respectively. The glycogen concentration of soleus and red gastrocnemius in EX-1HR group were about 1.9 and 1.8 times than that of N group, respectively, but the concentration of plantaris was not higher than that of N group. The glycogen concentration of liver in N group was 41.0+/-1.47mg/gm wet wt. and the concentration of the overnight fasted C group wad only 2.9% of the value of N group. The level of glycogen concentration of liver in the other glucose ingested groups(1HR, 2HR, including EX-1HR) was within 19 - 32% of that of N group. The blood glucose concentration of EX-1HR group was higher than that of N group, the plasma free fatty acid concentration of C and 2HR group was higher than that of N group, and the plasma insulin concentration of EX-1HR group was higher than that of N group. The concentration of supercompensated glycogen of soleus and red gastrocnemius were rapidly decreased during 30 minutes of exercise but there was almost no changes of the concentration during the other 30 minutes of continuing exercise. The concentration of N group during 30 minutes of exercise was decreased but more slowly than those of EX-1HR group. The remaining level of glycogen after 60 minutes of exercise in EX-1HR group was higher than that of N group. Taken together, the mobilization of endogenous muscle glycogen at the first stage of exercise was proportioned to the intial level of glycogen concentration, and later on, when exercise continued, the muscle glycogen level was stabilized. And the remaining level of supercompensated muscle glycogen after 60 minutes of exercise was higher than that of normally stored glycogen level. The mobilization of the glycogen stroed in slow and fast oxidative muscle fibers is faster than in the fast glycolytic muscle fibers during strenous exercise.

Effect of Acutely Increased Glucose Uptake on Insurin Sensitivity in Rats.: Yong Woon Kim, Youl In Ma, Suck Kang Lee; Yeungnam Univ J Med. 1997;14(1):53-66. Published online June 30, 1997; DOI: https://doi.org/10.12701/yujm.1997.14.1.53

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Abstract PDF: Insulin resistance is a prominent feature of diabetic state and has heterogeneous nature. However, the pathogenetic sequence of events leading to the emergence of the defect in insulin action remains controversial. It is well-known that prolonged hyperglycemia and hyperinsulinemia are one of the causes of development of insulin resistance, but both hyperglycemia and hyperinsulinemia stimulate glucose uptake in peripheral tissue. Therefore, it is hypothesized that insulin resistance may be generated by a kind of protective mechanism preventing cellular hypertrophy. In this study, to evaluate whether the acutely increased glucose uptake inhibits further glucose transport stimulated by insulin, insulin sensitivity was measured after preloaded glucose infusion for 2 hours at various conditions in rats. And also, to evaluate the mechanism of decreased insulin sensitivity, insulin receptor binding affinity and glucose transporter 4 (GLUT4) protein of plasma membrane of gastrocnemius muscle were assayed after hyperinsulinemic euglycemic clamp studies. Experimental animals were divided into five groups according to conditions of preloaded glucose infusion: group I, basal insulin (14+/-1.9 micronU/ml) and basal glucose (75+/-0.7 mg/dl), by normal saline infusion; group II, normal insulin (33+/-3.8 micronU/ml) and hyperglycemia (207+/-6.3 mg/dl), by somatostatin and glucose infusion; group III, hyperinsulinemia (134+/-34.8 micronU/ml) and hyperglycemia (204+/-4.6 mg/dl), by glucose infusion; IV, supramaximal insulin (100+/-2.2 mg/dl), by insulin and glucose infusion; group V, supramaximal insulin(4813+/-687.9 micronU/ml) and hyperglycemia (233+/-3.1 mg/dl), by insulin and glucose infusion. Insulin sensitivity was assessed with hyperinsulinemic euglycemic clamp technique. The amounts of preloaded glucose infusion(gm/kg) were 1.88+/-0.151 in group II, 2.69+/-0.239 in group III, 3.54+/-0.198 in groupIV, and 4.32+/-0.621 in group V. Disappearance rates of glucose (Rd, mg/kg/min) at steady state of hyperinsulinemic euglycemic clamp studies were 16.9+/-3.88 in group I, 13.5+/-1.05 in group II, 11.2+/-1.17 in group III, 13.2+/-2.05 in group IV, and 10.4+/-1.01 in group V. A negative correlation was observed between amount of preloaded glucose and Rd )r=-0.701, p<0.001) when all studies were combined. Insulin receptor binding affinity and content of GLUT4 were not significantly different in all experimental groups. These results suggest that increased glucose uptake may inhibit further glucose transport and lead to decreased insulin sensitivity.

The Charateristics of Glycogen Metabolism of Diaphragm in Rats.: Bok Hyun Nam, Eun Jung Kim, Suck Kang Lee; Yeungnam Univ J Med. 1997;14(1):46-52. Published online June 30, 1997; DOI: https://doi.org/10.12701/yujm.1997.14.1.46

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Abstract PDF: Diaphragm is though to play the most role in breathing and has a substantially greater proportion of slow oxidative and fast glycolytic fibers, and low proportion of fast oxidative fibers. The respiratory muscle, diaphragm, has the functional characteristics of slow speed of contraction, high resistance to fatigue and the ability to respond to intermittent ventilatory loads, for example of exercise. In the present study, the characteristics of the metabolism (depletion and repletion) of glycogen and the structural changes of diaphragm during depletion and repletion of glycogen were observed in rats. For comparison, the red gastrocnemius muscle which has a greater proportion of fast oxidative glycolytic (FOG) and slow oxidative (SO) fibers, and low proportion of fast glycolytic (FG) fiber, was also studied. The glycogen concentration of diaphragm in overnight fasted rats was 2.30+/-0.14mg/gm wet weight. The values of glycogen concentration at 60, 90 and 120minutes of treadmill exercise loaded rats was significantly decreased compared to that of the overnight fasted rats. There was no significant difference among the glycogen concentration of diaphragm at 60, 90 and 120minutes of exercises. The glycogen concentration of diaphragm was decreased to 1.12+/-0.17 from 2.30+/-0.14mg/gm wet weight by treadmill exercise. The glycogen depletion rats of diaphragm during exercise was faster than that of red gastrocnemius in both of the first 60minutes and 120minutes duration of exercise. The glycogen repletion of diaphragm after intragastric glucose administration by stomach tube was studied in control and exercise groups. The glycogen concentration was significantly increased after glucose administration in both of the control and exercise groups. All of the concentration of exercise group at 60, 120 and 180minutes after glucose administration was significantly higher than those of control group. In conclusion, one of the characterics of diaphragm in glycogen metabolism is fast glycogen depletion during exercise, and slowness of glycogen repletion after glucose ingestion in rats.

Insulin Resistance in Late Pregnant Rats.: Myung Heup Chun, Yong Woon Kim, So Young Park, Jong Yeon Kim, Suck Kang Lee; Yeungnam Univ J Med. 1995;12(2):319-330. Published online December 31, 1995; DOI: https://doi.org/10.12701/yujm.1995.12.2.319

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Abstract PDF: The influence of normal late pregnancy on insulin action and insulin secretion was studied in the Sprague-Dawley female rats. On 20th day after mating, intravenous glucose tolerance test(IVGTI) was performed in non pregnant control and pregnant rats. As results of IVGTT, glucose disappearance rate was not significantly different in both groups, but secretory response of insulin was significantly(p<0.05) increased in pregnant rat. And the ratio of insulin/ .glucose was significantly higher in pregnant rats, which means existence of insulin resistance. These insulin resistance was overcomed by increased secretory response of pancreatic insulin. Insulinogenic index( A insulin/glucose - 5 min) was highly significantly (r=0.62, p<0.01) correlated with progesterone concentration. Glycogen level and amounts of "C-glucose incorporated into glycogen after IVGTT were significantly(p<0. 05) decreased in the liver, but were not changed significantly in soleus. Glycogen synthase activity of soleus and liver was not differ significantly in the both groups. Insulin binding at varying concentrations of insulin to crude membrane of pregnant liver was not significantly different from control. In conclusions, although these pregnant rats were normal glucose tolerance due to increased secretory response of insulin, that was correlated with progesterone concentration, pregnant rat had insulin resistance. The mechanisms of insulin resistance were not related to defect of insulin binding phase and glycogen synthase, but suggest pre-receptor and/or postreceptor phase.

Effect of Persistent Mild Hyperglycemic Hyperinsulinemia on Development of Insulin Resistance in Rats: Yong Woon Kim, Jin Hyun Park, So Young Park, Jong Yeon Kim, Suck Kang Lee; Yeungnam Univ J Med. 1995;12(2):269-281. Published online December 31, 1995; DOI: https://doi.org/10.12701/yujm.1995.12.2.269

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Abstract PDF: The effect of persistant mild hyperglycemic hyperinsulinemia on the development of the insulin resistance in rats was studied in vivo. Also, the characteristics of the insulin resistance compared with the insulin resistance of STZ diabetic rats. Persistant mild hyperglycemic hyperinsulinemic rat model was produced by ingestion of glucose polymer for 8 days. The glucose disappearance and infusion rate was measured by hyperinsulinemic euglycemic clamp to"Imique at steady state of blood glucose and insulin levels. The clamped level of blood glucose was 100 mg/dl, and the clamped levels of insulin were 70 pU/ml (physiologic condition) and 3000 pU/ml (supramaximal condition). Hepatic glucose producticon rate was calculated using measured data. And the glycogen synthetic capacity of skeletal muscle (soleus) and liver was measured after 2 hours of hyperinsulinemic euglycemic clamp study. The glucose disappearance and glucose infusion rate in glucose polymer group was decreased in the both physiological and supramaximal insulin level compared to the rate of the normal control group. The rate of STZ diabetic group was lowest at supramaximal insulin level among two another experimental groups. The hepatic glucose production rate of glucose polymer group was decreased compared to normal control but increased in STZ diabetic group. The glycogen synthetic capacity of skeletal muscle and liver of glucose polymer group was not significantly different from normal control group, but it was markedly decreased in STZ diabetic group. These results suggest that persistant mild hyperglycemic hyperinsulinemia may induce insulin resistance, but glycogen synthetic capacity is intact.

Insulin Resistance in the Peripheral Tissue.: Suck Kang Lee, Jong Yeon Kim; Yeungnam Univ J Med. 1994;11(1):1-15. Published online June 30, 1994; DOI: https://doi.org/10.12701/yujm.1994.11.1.1

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Abstract PDF: No abstract available.

The effect of regular physical exercise on glucose uptake in soleus and intravenous glucose tolerance in streptozotocin diabetic rats.: Myung Heup Chun, Yong Woon Kim, Jong Yeon Kim, Young Man Lee, Suck Kang Lee; Yeungnam Univ J Med. 1992;9(1):121-129. Published online June 30, 1992; DOI: https://doi.org/10.12701/yujm.1992.9.1.121

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Abstract PDF: The effect of exercise on plasma insulin, free fatty acid, and glucose uptake and glycogen concentration in soleus, and intravenous glucose tolerance of streptozotocin treated, diabetic Sprague-Dawley rats were studied. Diabetic-trained animals were subjected to a regular program of treadmill running for 4 weeks. Seventy-two hours after the last training session, basal and insulin-stimulated glucose uptake was studied in incubated strips (about 20 mg) of soleus muscle in vitro. Glucose tolerance was measured with intravenous infusion of 0.5 g glucose/kg body weight. In diabetic rats, training was associated with increase glucose uptake in basal and maximal insulin concentrations, decreased fasting glucose concentrations, and increased muscle glycogen levels, but there were no changes in glucose tolerance curve and plasma insulin concentrations. These results suggest that regular running program for 4 weeks improve responsiveness of insulin on soleus muscle, but fails to cause improvement of impaired intravenous glucose tolerance in mild degree streptozotocin induced diabetic rats.

Effects of insulin and exercise on glucose uptake of skeletal muscle in diabetic rats.: Jin Hyun Park, Young Woon Kim, Jong Yeon Kim, Suck Kang Lee; Yeungnam Univ J Med. 1990;7(1):29-37. Published online June 30, 1990; DOI: https://doi.org/10.12701/yujm.1990.7.1.29

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Abstract PDF: The effects of insulin and exercise on glucose uptake of skeletal muscle were investigated in soleus muscle isolated from low dose streptozotocin induced diabetic rat in vitro. Glucose uptake was assessed by measuring ³H-methylglucose uptake in vitro. Basal glucose uptake in diabetes was reduced by approximately one-third of the control value (5.6±0.73µMol/g/20min. in diabetes versus 8.4±0.77 in control, P<0.01). There was also a significant decrease (P<0.01) in glucose uptake of diabetes at physiologic insulin concentration (200 µIU/ml) by 40% (6.1±1.20 versus 10.0±0.81). Furthermore, maximal insulin (20000 µIU/ml)-stimulated glucose uptake was 36% lower in diabetes as compared with control (7.3±1.29 versus 11.4±1.29, P<0.01). In contrast, exercise (1.0 km/hr, treadmill running for 45 min.) effect on glucose uptake was so dramatic in diabetes that glucose uptake at basal state was 8.+1.09 and insulin stimulated-glucose uptake were 10.2±1.47 and 11.9±1.64, in 200 and 20000 µIU/ml added insulin, respectively. These results suggest that insulin insensitivity develops in skeletal muscle after 2 weeks of streptozotocin-induced diabetes, but these insensitivity was recovered significantly by single session of running exercise.

Glucose incorporation into glycogen molecules of hypertrophied slow and fast twitch muscles in vitro.: Yong Woon Kim, Jong Yeon Kim, Suck Kang Lee; Yeungnam Univ J Med. 1990;7(1):19-27. Published online June 30, 1990; DOI: https://doi.org/10.12701/yujm.1990.7.1.19

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Abstract PDF: This investigation was undertaken to clarify the in vitro effect of the various stimulations, such as exercise (E), insulin (I) direct electrical stimulation (EST) and the combinations of the above, on the glucose incorporation intro glycogen molecules (glycogen synthesis) of the normal slow (soleus) and fast twitch (plantaris) muscles, and the different responses of slow and fast twitch muscles to persistent overloads causing compensatory muscle hypertrophy. In resting state, slow twitch muscle has greater capacity for glycogen synthesis than fast twitch muscle, and responses of different muscle to various stimuli were differ as follows: In slow twitch muscle, the glycogen synthesis was increased by insulin, and electrical stimulation but not increased by exercise; exercise increased insulin sensitivity and the effect of electrical stimulation. Whereas the glycogen synthesis in fast twitch muscle was increased only by the stimuli combined with E and EST, and E, I, and EST. As the result of removal of synergistic muscle, both muscles were hypertrophied, and the degree of hypertrophy in response to persistent overload was higher in fast twitch muscle (182%) than slow twitch muscle (151%). In hypertrophied muscles, glycogen synthesis of soleus in any groups was lower than that of the control, but similar in plantaris. In conclusions, there were marked heterogeneity in different muscle fiber in the effects of exercise and insulin addition and electrical stimulation on muscle glycogen synthesis, and fast twitch muscle may be adapted more easily to that kind of persistent overload than slow twitch muscle.

A Design of High-Frequency Oscillatory Ventilator Using Phase Lock Loop system.: Sang Hag Lee, Dong Gyo Jeong, Joon Ha Lee, Kwan Ho Lee, Young Jo Kim, Jae Chun Chung, Hyun Woo Lee, Suck Kang Lee, Tae Sug Lee; Yeungnam Univ J Med. 1989;6(2):217-222. Published online December 31, 1989; DOI: https://doi.org/10.12701/yujm.1989.6.2.217

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Abstract PDF: In this study, high frequency oscillatory ventilator was designed and constructed. Using designed by phase-lock loop system, in order to accurately and easily treat both the outlet volume and rpm. A system has been designed and is being evaluated using CD4046A PLL IC. We use this PLL IC for the purpose of motor controls. The device consists of PLL system, pumping mechanism, piston, cylinder, and special crank shaft are required. This system characteristics were as follows: 1) Frequency: 20-1800 rpm 2) Outlet air volume: 1-50 cc

Factors influencing arterial CO² tension in cats during high frequency oscillation ventilation.: Jun Young Do, Jae Yick Lee, Kwan Ho Lee, Yeung Jo Kim, Jae Chun Chung, Hyun Woo Lee, Suck Kang Lee; Yeungnam Univ J Med. 1989;6(2):47-55. Published online December 31, 1989; DOI: https://doi.org/10.12701/yujm.1989.6.2.47

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Abstract PDF: High frequency ventilation (HFV) is a new ventilatory technique that uses very small tidal volume (less than the anatomic dead space) and high frequency, and classified 4 distinct types according to frequency and mode of gas delivery. The mechanism of gas transport of high frequency oscillation ventilation (HFOV) is somewhat different to other types of HFV. To evaluate the determinants of PaCO² in HFOV, a study was done with a HFOV on 9 cats, and the results are: 1) PaCO² was not correlated with frequency at the constant stroke volume (6 voltage) and bias flow (6 L/minutes). 2)PaCO² was correlated with stroke volume but not with bias flow under the constant frequency (15 Hz/min) and bias flow (3 to 6 L/min). From above results, the main determinant of PaCO² on artificial ventilation with HFOV was stroke volume, but further study between flow, the site of delivery to the airway and humidification of bias flow and CO² elimination is required in future research.

The Effect of Exercise on the Conversion Rate of Ingested Glucose to Glycogen in the Hindlimb Skeletal Muscles in Rats.: Kyung Hwa Jung, Jong Yeon Kim, Yong Woon Kim, Suck Kang Lee; Yeungnam Univ J Med. 1988;5(2):79-86. Published online December 31, 1988; DOI: https://doi.org/10.12701/yujm.1988.5.2.79

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Abstract PDF: In the present study the effect of exercise on the conversion rate of ingested glucose to glycogen in the different types of hindlimb skeletal muscles in Sprague-Dawley male rats was studied. The amounts of synthetized glycogen from ingested glucose of fast-twitch white (WV), fast-twitch red (RV), mixed type of fast-twitch white and red (EDL), and slow-twitch (SOL) muscles were determined at 30 and 90 min. after ingestion of 25% glucose solution which contained 14C-glucose(2 ml(luCi)/100gm B.W.) in control and exercise loaded rats. The result was summarized as follows: The about 55% at 30 min. and 70% at 90 min. after glucose ingestion were absorbed from gastrointestinal tract. This result shows no effects of exercise on absorption rate from gastrointestinal tract. The amount of synthetized glycogen of SOL from ingested glucose at 30 and 90 min. after glucose ingestion were highest, whether WV were lowest in hindlimb skeletal muscles in control and exercise loaded rats. In the exercise loaded rats, the amounts of synthetized glycogen of SOL, RV, and EDL at 90 min. after glucose ingestion was much higher than control rats, but not different in WV between exercise-loaded and control rats. At 30 min. after glucose ingestion, only SOL of exercise loaded rats was higher than control rats. In the control rat, the synthesis of glycogen was almost completed during initial 30 minutes. On the other hand, in the exercise loaded rat, except WV was opposite result of control rats, i.e., amounts of synthetized glycogen were major during late period. The amount of synthetized glycogen of liver at 30 and 90 min. after glucose ingestion in exercise loaded rats was higher than control rats. The rate of glycogen synthesis in control and exercise loaded rats were higher between 30-90 minute than initial 30 minutes.

Effect of Short Termed Fasting on the Usage Patterns of Metabolic Energy Sources during Exercise in Man.: Jong Yeon Kim, Young Man Lee, Suck Kang Lee; Yeungnam Univ J Med. 1986;3(1):269-278. Published online December 31, 1986; DOI: https://doi.org/10.12701/yujm.1986.3.1.269

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Abstract PDF: The purpose of this study was to know the effect of short termed fasting on the usage of metabolic energy sources and the metabolic differences between non-athletic and athletic subjects. Subjects were divided into non-athletic and athletic group and exercise was loaded on both groups after feeding and fasting. Exercise was loaded by a treadmill running at the speed of 8 km/hour for 30 minutes in both groups. The experiment yielded following results. In the fed state, the level of plasma FFA increased markedly after 15 and 30 minutes of exercise compared with it's level of pre-exercise period in both groups. In the fated state, the level of plasma FFA in non-athletic group increased steadily according to the duration of exercise, while it's level in athletic group showed no changes. At pre-exercise period, the level of plasma FFA was higher in fasted state than fed state. Immediately before the exercise and 15 and 30 minutes after the exercise, blood for the determination of plasma free fatty acid (FFA), glucose, triglyceride (TG) and cholesterol was sampled from antecubital vein, and simultaneously heart rate was measured. In the fed state, the level of plasma glucose was increased mildly according to exercise, and in the fasted state it's level increased according to exercise in both groups also. In the fasted state, the level of plasma TG was lower than that in the fed state. The level of plasma TG and cholesterol in the fed state was no changed by the exercise from the pre-exercise period. The level of plasma cholesterol in athletic group had tendency to lower than that in non-athletic group. Heart rate increased markedly according to exercise in both groups, but the athletic group's increasing rate of heart rate was lower than the non-athletic group's heart rate increased according to exercise and athletic groups heart rate increased early period of exercise, but did not change during latest post-period of exercise.

Effect of Betamethasone on Pulmonary Surfactant Activity in Unilateral Pneumonectomized Rabbits.: Suck Kang Lee, Young Man Lee; Yeungnam Univ J Med. 1984;1(1):59-66. Published online December 31, 1984; DOI: https://doi.org/10.12701/yujm.1984.1.1.59

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Abstract PDF: Although it is well established that steroid is effective for treatment of neonatal respiratory distress syndrome (NRDS), the action mechanism of steroid on NRDS is not well known. Several authors have insisted that steroid increases secretion of pulmonary surfactant from type II pneumocyte, but others have insisted that steroid does not affect the secretory function of the type II pneumocyte. And some authors have suggested that steroid may cause compositional change of pulmonary surfactant phospholipid. From these aspects, it is desirable to confirm the effect of steroid on the secretory function of the type II pneumocyte. In order to know the effect of steroid on pulmonary surfactant activity, phospholipid phosphorus of lung lavage was measured and composition of pulmonary surfactant phospholipid of lung lavage was analyzed by thin layer chromatography (TLC) in control (c), pneumonectomized (PN), and pneumonectomized with betamethasone treated (PNS) rabbits. And lung weight and lung weight-body weight ratio were measured in each experimental group also. In PN group, right lung pneumonectomy was performed as PN group, and one day after the surgery, betamethasone was injected for four days intramusculary (4 mg/day) and rabbits were sacrificed. The experiment yielded following results. PNS group's lung weight was significantly (p<0.01) heavier than C group's, but in comparison with PN group's it showed no significant change. PNS group's L/B ratio was significantly (p<0.05) higher than C group's, but compared with PN group's it showed no significant change. The value of phospholipid phosphorus content of PNS group was significantly (p<0.01) higher than that of C group. Even if the value of phospholipid phosphorus content in PNS group was not significantly higher than that of PN group, it showed increasing tendency compared with that of PN group. And in an analysis of the thin layer chromatogram, quantity (µmol/gm of wet weight lung) of phosphatidylcholine in PNS group decreased significantly (p<0.05) compared with C and PN group. From these results, it may be suggested that though steroid inhibits cellular hyperplasia in the compensatory growing lung, it auguments the secretory function of type II pneumocyte and causes compositional change of pulmonary surfactant phospholipid.

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